Exactly one year shy of Charles Darwin's 200th birthday, scientists are looking ahead to the anniversary to call for renewed understanding of the scientist's powerful impact on Western civilization.

None of modern biology, no advances in medical research, nor success for the Human Genome Project, nor the achievements of biotechnology could exist today without the insights first advanced by that reclusive genius of the Victorian era, the scientists agree.

Now, a UC Berkeley paleontologist named Kevin Padian argues that the coming bicentennial is the ideal time "to reflect on just what constitutes Darwin's enduring greatness in Western thought."

And this week, the 199th anniversary of Darwin's birth on Feb. 12, 1809, hundreds of public meetings reflecting on his discoveries will be held at "Darwin Day" celebrations around the world.

In a seminal essay published in this week's issue of the international journal Nature, Padian says of the great Victorian scientist, explorer and meticulous researcher: "Perhaps no individual has had such a sweeping influence on so many facets of social and intellectual life" as Darwin.

At the same time, Padian notes, "Darwin has been invoked as the demon responsible for a variety of heartless ills of society." Among them, he Padian lists "atheism, Nazism, communism, abortion, homosexuality, stem cell research, same-sex marriage, and the abridgment of all our natural freedoms."

Indeed, Darwin has been demonized by many, and his findings contradicted by those who deny the facts of evolution.

His opponents argue that Darwin's concept of evolution is still merely an untested theory, but hold conflicting views on how life began and humanity arrived on Earth. There are the creationists, who insist that the Bible's descriptions of the world's beginning and the first humans are literally true. Then, there are more than a few rebel scientists who argue that the infinite varieties of life forms are so complex that they must be the product of some kind of intelligent design. Padian, a professor of integrative biology at Berkeley, is also president of the Oakland-based National Center for Science Education, a watchdog group that monitors controversies over evolution in the schools and promotes curricula based on the latest science.

Two years ago, he provided key testimony during the widely watched trial against the Dover, Pa., school board, which ended when a federal judge ruled that promoting intelligent design as science in a public school - as board members sought - was unconstitutional. The judge concluded that the idea of "design" is not science but merely "an untested alternative hypothesis grounded in religion" and could not be presented in science classrooms as it violated the separation of church and state.

Advocates of intelligent design are the loudest voices today in the attacks on Darwin's most influential work, "On the Origin of Species," subtitled "By Means of Natural Selection," which was published 150 years ago. A stormy debate over that subtitle began at once and has never stopped.

Believers in intelligent design insist that the tenets of evolutionary theory are deeply flawed and that humans and other animals could never have evolved from more primitive species.

The advocates of intelligent design, or ID, cite the human eye, for example, as an organ so incredibly complex that it could not possibly have evolved step-by-step over millions of years. Each separate part of an eye must function together in concert, the ID advocates insist, and so the organ must have been assembled fully and completely, like a machine, by some unknown and as-yet-unidentified Designer.

In Padian's Nature article, the Berkeley scientist notes that Darwin was already well aware of what paleontologists and other scientists call deep time - the "incredible stretch of time" that was needed for major environmental changes to influence the survival of plants and animals so the hardiest could pass on their characteristics, while the least fit would not survive.

"It was no longer possible," Padian says of Darwin and his day, "to accept that Earth was 6,000 years old, as some biblical scholars estimated."

Based on Darwin's discoveries during his five-year voyage around the world as a naturalist aboard the British ship HMS Beagle, and on his research in England, where he scoured the countryside recording the experiences of animal and plant breeders, Darwin also wrote an equally important volume, "The Descent of Man, and Selection in Relation to Sex."

As Padian puts it: "Differences between sexes could now be explained as the result of processes of mate choice and territorial competition, not merely of divine design."

High school students in biology classes whose teachers describe Darwin's work often recommend his informal and absorbing book, "The Voyage of the Beagle," in which the young naturalist recalled the varied finches he observed when the Beagle stopped in the Galapagos Islands. By no means irreligious, the scientist also wrote of the life that arose after the volcanic islands' emergence from the sea. "Hence, both in space and time, we seem to be brought somewhat near to that great fact - that mystery of mysteries - the first appearance of new beings on this earth."

Says Padian in his Nature essay on Darwin's work, "Today we can identify groups of plants and their insect predators, vertebrates and their parasites, lichens composed of an alga and a fungus, and many other associations that can only be reasonably explained by co-evolution through diversification over millions of years."

Genes were unknown in Darwin's time, so the precise genetic details of how plants and animals changed and evolved were still a mystery. But today, the genes that regulate the development of animals and humans have been decoded in detail, Padian noted in an interview, and, remarkably, they turn out to be exactly the same in all organisms.

"Finding the genetic basis of evolutionary development is really amazing," Padian said, "and it vindicates Darwin's view of the tree of life completely."

Celebrating Darwin

As Charles Darwin's 200th birthday approaches, public meetings reflecting on his discoveries will be held around the world.

On the Web go to

links.sfgate.com/ZCJR

links.sfgate.com/ZCJQ

To hear a podcast with UC Berkeley paleontologist Kevin Padian, go to sfgate.com/podcasts